What do you want out of your intake and exhaust mods?

OEM intake and exhaust are designed to flow the maximum power your engine makes stock. They are very mature technologies so there's not a lot of sacrifices needed to satisfy all goals (such as noise, emissions, durability, power, etc). Sometimes there are slight compromises (funny-shaped silencer on intake tube, crush-bent exhaust where mandrel-bent would be better), but not effectively much in modern cars.

1. Fuel economy - no. They'd be crazy to leave some fuel economy on the table. Fuel economy lets them put in more power and still meet CAFE requirements. Power sells cars (and sometimes fuel economy too). Anyway intake and exhaust can't affect anything unless you're making 100% of your engine's maximum power, which is not something you do while trying to go easy on your wallet.

2. Power - no, unless you've done other mods to the engine. Again, the manufacturer would be crazy to leave power on the table. Power sells cars. At the very least you'll need a tune to complete the intake-engine-exhaust trifecta and get something worthwhile out of your mods. Also, look at your intake now; I bet it already takes cold air from behind the grille or in the fender.

3. Sound and look - yes. You can definitely get these results.

CAIs and catbacks are popular because they're easy, inexpensive, marketed well, and have a whole lot of market momentum from back when OEM systems were not designed so well (my 1980 Buick gets warm underhood air like a short ram and apparently they hired a chimpanzee to design the exhaust).

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1980 Buick LeSabre 4.1L 5MT

Put your car in your sig!

Learn to launch/FAQs/lugging/misused terms: meta-sig

In many cases, yes. Often fuel economy is sacrificed for sound. My car, for example, picks up about 1mpg (ooooo lots) with an open intake, but becomes much louder. Most consumers dont want loud. Of course things are always a bit different in the turbo world.

Just to add some extra information and prove a different one of your points as correct, my factory airbox has been tested to be free flowing up to 400hp. Its only in extreme situations that there is a real need to replace it with a different intake.

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Maybe I should redirect my way of thinking. What sorts of mods should I look into? I'm not looking to make a 400WHP beast, nor am I trying to rice it out. I just want a fun car on a budget. (not that it's not already fun)

I also want an exhaust that will bring out more of the rumble of the boxer

and also a new pic:

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Two pedals, two feet, too easy.

Car: 2007 Impreza 2.5i Special Edition
http://www.standardshift.com/forum/viewtopic.php?f=32&t=13230

You may want to define "fun" in more detail.

For power I'd consider a tune first, then maybe upgrade intake and exhaust.

How about non-ricey suspension mods?

Or, you could spend that money on some track time somewhere...track time in stock Impreza > road time in modified car (probably).

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1980 Buick LeSabre 4.1L 5MT

Put your car in your sig!

Learn to launch/FAQs/lugging/misused terms: meta-sig

Although probably obnoxiously loud and ricey looking, if HKS makes an exhaust for your car, do it. They sound wonderful on Subaru boxers.

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1994 Corolla - 1990 Miata

Hey, the water isn't frozen. I thought you moved, but you were still in Canada.

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'08 Jeep Liberty 6-Speed MT - "Last of the Mohicans"

Funny Guy!

That's actually an inlet of the ocean. I don't think that water ever freezes. Most of the lakes around here were frozen up until a couple of weeks ago though.

East coast weather sucks.

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Two pedals, two feet, too easy.

Car: 2007 Impreza 2.5i Special Edition
http://www.standardshift.com/forum/viewtopic.php?f=32&t=13230

You do know that it's a rebadged Pontiac Grand Am, right?

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'08 Jeep Liberty 6-Speed MT - "Last of the Mohicans"

Nice car, congrats!! I had an '07 special edition wagon (auto though :-\), definitely enjoyed it.

The stock exhaust isn't bad for a stock exhaust, sounds a lot better than most cars in that class. I always wanted a Borla exhaust for mine (and headers too), they sound sick. Check this out, it's just headers:
http://www.youtube.com/watch?v=SkvETX5ISgY
Never did it though since mine was an auto.

The suspension is decent in the sedan (the wagon I had used a different front suspension, it had a lot of roll). Upgrades . . . I'd get some HIDs in there, maybe put some yellow covers on the fogs, and get some decent mud flaps. Get the HIDs done right though, you don't want it to look like rice (stay away from high K value bulbs, which are too blue).
For mud flaps, I had these on mine, they were big and looked badass.
http://www.rallyarmor.com/store/rally-m ... -c-60.html

Might consider an upgraded shift knob down the line too, you can get STI ball ones. Not sure if they sell a short shift kit but that would be worth looking into as well.

Lastly Subaru sells great all-season rubber floor mats, I picked mine up for about $40 at the dealer.

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2011 BMW E92 335i: Le Mans Blue, M Sport, 6MT w/ CDV Mod, BMW Performance Exhaust + Style 269 19" Wheels

It is not uncommon to see factory turbo cars pick up real (and measurable) power with a cat-back exhaust. So if you have a turbo car, you just might see some real gains with nothing more than an aftermarket exhaust.

Back in my Diamond Star days, I purchased an HKS exhaust and with no other mods, the turbo boost increased by a bit more than 1 psi. The idea is that a freer flowing exhaust will spool the turbo more and increase the boost pressure. This was a big selling point in the HKS catalog and I was pleasantly surprised to see that the claim was 100% accurate. It might not work on today's cars because I think the boost levels are controlled in other ways now.

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Boost control valves are the devil

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Yup, I eventually put one on my Diamond Star. It was an EVC, made by HKS. The funny thing was that I could easily bump the boost pressure up manually be bleeding off some of the vacuum to the wastegate. The EVC allowed me to dial in two pre-sets for boost and a third with an adjustable dial that I could control from the driver's seat. It was great technology back in those days, and it really woke up the engine. I used to run 20 lbs of boost, which was almost 9 more than the stock.

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Sadly my car is N/A, not turbo. It seems like most of the aftermarket stuff is directed towards the WRX/STi market. Probably because the majority of people who buy the 2.5i aren't concerned with tuning. Also because you probably get better results tuning a turbo car.

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Two pedals, two feet, too easy.

Car: 2007 Impreza 2.5i Special Edition
http://www.standardshift.com/forum/viewtopic.php?f=32&t=13230

That sounds pretty good. Ultimately I'd like it to sound something like this:



I might also look into the HIDs.

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Two pedals, two feet, too easy.

Car: 2007 Impreza 2.5i Special Edition
http://www.standardshift.com/forum/viewtopic.php?f=32&t=13230

So here's what I'm thinking. I'm taking in more money that I thought I would be (win!) so I'm thinking I may (may) be able to start doing some smaller mods soon. (I still owe a fair bit of money for some stuff)

To start off I'm thinking a short shifter and new bushings. Hopefully that'll get rid of some of the slop/mush in the gearbox.

I'd also like to get a new set of rims/tires and keep the stock rims for winter (although I may just rock the steelies)

I'm thinking about bumping up to a 17" rim/tire and getting something like this:



or



Later down the road I'd like to do a proper exhaust and get some unequal length headers and whatnot.

What do you think?

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Two pedals, two feet, too easy.

Car: 2007 Impreza 2.5i Special Edition
http://www.standardshift.com/forum/viewtopic.php?f=32&t=13230